Zopid Kakuro -Electronic Illuminated Touch Screen Puzzle Game With Back Light - Pocket Sized Mathematical Logic Puzzles HANDHELD LOGIC PUZZLES - Features a compact, hand-held elctronic puzzle with large LCD screen (2x 2.5 inch) that comes with thousands of challenging mathematical logic puzzle games. It has a backlight and is suitable for both day and night use. TOUCH SCREEN WITH STYLUS - Comes with a stylus. Easy to touch and play. Puzzle can only use the numbers 1 through 9 and no digit can be duplicated in the same row or column (see product description for details) CHALLENGING LEVELS - User selectable 5 difficulty levels. Each level can automatically generate thousands of fascinating puzzles. FUNCTIONALITY - 3 hints available for every game. Comes with different functionalities - Check and reminder functions for wrong answers and resume Function to continue game where you left it the last time. BATTERY OPERATED - Uses 2 "AA" batteries (not included). There is an "Auto shut off" option to save the battery life.